Suppose we have a graph of y = xsquared + 3x -2. What lines would you draw on it to solve the following eqautions?
a) xsquared + 3x + 5 = 0
b) xsquared + 4x -4 = 0
c) xsquared -x - 1 = 0
Hello, Natasha1!
I'll do one of them . . .
Suppose we have a graph of $\displaystyle y \:=\: x^2 + 3x -2.$
What lines would you draw on it to solve the following eqautions?
$\displaystyle b)\;\;x^2 + 4x -4 \:=\: 0$
Draw the line $\displaystyle y \:=\:-x + 2$ . . . . why?
To find the intersections of the parabola and the line,
. . we have: .$\displaystyle x^2+3x-2 \:=\:-x + 2 \quad\Rightarrow\quad x^2 + 4x - 4 \:=\:0 $
The $\displaystyle \,x$-coordinates of the intersections are the roots of the quadratic equation.